[Bug c++/104539] Failed to inline a very simple template function when it's explicit instantiated.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104539 Andrew Pinski changed: What|Removed |Added CC||programmerjake at gmail dot com --- Comment #6 from Andrew Pinski --- *** Bug 71587 has been marked as a duplicate of this bug. ***
[Bug c++/104539] Failed to inline a very simple template function when it's explicit instantiated.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104539 Jason Merrill changed: What|Removed |Added Known to fail|12.0| Known to work||12.0 Status|ASSIGNED|RESOLVED Target Milestone|--- |12.0 Resolution|--- |FIXED --- Comment #5 from Jason Merrill --- Fixed for GCC 12.
[Bug c++/104539] Failed to inline a very simple template function when it's explicit instantiated.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104539 --- Comment #4 from CVS Commits --- The master branch has been updated by Jason Merrill : https://gcc.gnu.org/g:2c9b7077b72529fbbe896212a0088bff6025c5e7 commit r12-7288-g2c9b7077b72529fbbe896212a0088bff6025c5e7 Author: Jason Merrill Date: Thu Feb 17 00:04:21 2022 -0500 c++: inlining explicit instantiations [PR104539] The PR10968 fix cleared DECL_COMDAT to force output of explicit instantiations. Then the PR59469 fix added a call to mark_needed, after which we no longer need to clear DECL_COMDAT, and leaving it set allows us to inline explicit instantiations without worrying about symbol interposition. I suppose there's an argument to be made that an explicit instantiation declaration (extern template) should clear DECL_COMDAT, since that suggests that there will be only a single instantiation somewhere that could be subject to interposition, but that doesn't change the 'inline' semantics, and it seems cleaner to treat template instantiations uniformly. PR c++/104539 gcc/cp/ChangeLog: * pt.cc (mark_decl_instantiated): Don't clear DECL_COMDAT. gcc/testsuite/ChangeLog: * g++.dg/ipa/inline-4.C: New test.
[Bug c++/104539] Failed to inline a very simple template function when it's explicit instantiated.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104539 Jason Merrill changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |jason at gcc dot gnu.org
[Bug c++/104539] Failed to inline a very simple template function when it's explicit instantiated.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104539 --- Comment #3 from Jason Merrill --- (In reply to Richard Biener from comment #2) > the explicit instantiation lacks COMDAT (but has comdat_group) and it > has forced_by_abi. > > I'm not sure the C++ standard calls out any semantic difference for > explicit vs. implicit instantiations but maybe the Itanium ABI does. The ABI says nothing about explicit vs. implicit instantiations. mark_decl_instantiated cleared DECL_COMDAT to fix PR10968, where we failed to emit an explicit instantiation. But that was before mark_needed; now that we have that, I'd think it makes sense to have DECL_COMDAT set on explicit instantiations just like implicit ones.
[Bug c++/104539] Failed to inline a very simple template function when it's explicit instantiated.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104539 Richard Biener changed: What|Removed |Added Keywords||missed-optimization Last reconfirmed||2022-02-15 Component|tree-optimization |c++ Ever confirmed|0 |1 CC||hubicka at gcc dot gnu.org, ||jason at gcc dot gnu.org Status|UNCONFIRMED |NEW Known to fail||12.0 --- Comment #2 from Richard Biener --- t.ii:9:20: missed: not inlinable: int g()/1 -> int f() [with int = 0]/0, function body can be overwritten at link time so the issue seems to be that explicitely instantiating changes _Z1fILi0EEiv/1 (int f() [with int = 0]) @0x76697220 Type: function definition analyzed Visibility: semantic_interposition public weak comdat comdat_group:_Z1fILi0EEiv one_only Aux: @0x42d7d00 References: Referring: Function flags: body Called by: _Z1gv/0 Calls: to _Z1fILi0EEiv/0 (int f() [with int = 0]) @0x76697000 Type: function definition analyzed Visibility: forced_by_abi semantic_interposition public weak comdat_group:_Z1fILi0EEiv one_only Aux: @0x76697220 References: Referring: Function flags: body Called by: _Z1gv/1 (can throw external) Calls: the explicit instantiation lacks COMDAT (but has comdat_group) and it has forced_by_abi. I'm not sure the C++ standard calls out any semantic difference for explicit vs. implicit instantiations but maybe the Itanium ABI does. Jason? Honza?
